Fiberoptic bronchoscopy is well established as a useful tool in the diagnosis of suspected cases of pulmonary tuberculosis that are sputum smear-negative. However, little attention has been focused on the role of transbronchial biopsy culture in the bacteriologic diagnosis of the disease. In this series of 12 patients with culture-proven pulmonary tuberculosis, we reviewed the results of transbronchial biopsy culture in comparison to the culture of prebronchoscopy sputa, postbronchoscopy sputa and bronchial washings. We found that transbronchial biopsy culture yielded positive cultures in only 16 percent (2/12) of these cases of proven tuberculosis and that transbronchial biopsy culture was not an exclusive source of culture-positive material in any of the patients studied. Although fiberoptic bronchoscopy may be quite helpful in establishing the diagnosis of tuberculosis in patients that are sputum smear-negative, our findings indicate that culture of transbronchial biopsy specimens contribute little to the bacteriologic diagnosis.